diff --git a/pyproject.toml b/pyproject.toml
index 213d39d..9dba14f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,8 +31,8 @@ dependencies = [
     "numba>=0.55.0",
     "xarray>=0.20.2",
 ]
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 
 
 [project.urls]
-Homepage = "https://github.com/simonrp84/PyCoxMunk"
\ No newline at end of file
+Homepage = "https://github.com/simonrp84/PyCoxMunk"